1. Field of the Invention
The present invention relates to an anthracene compound and a chemiluminescent composition comprising the compound, and more particularly to a novel anthracene compound which is capable of emitting a blue light of a high intensity for a prolonged period of time compared with conventional anthracene compounds used as luminescent dyes in chemiluminescent compositions emitting blue light, and a chemiluminescent composition comprising the novel compound.
2. Description of the Related Art
One example of known chemiluminescent solutions includes a mixed solution of a chemiluminescent oxalate composition comprising a luminous dye and a solution containing peroxide.
The chemiluminescent oxalate composition generally contains a luminescent dye, an oxalate and a solvent. The peroxide-containing solution contains peroxide, a catalyst and a solvent.
The color of light generated from the chemiluminescent solution is determined by the luminescent dye used in the chemiluminescent oxalate composition. As the luminescent dye emitting a blue light, an anthracene compound is known.
As the anthracene compound emitting a blue light, a 9,10-diphenylanthracene compound described in the following formula 1 and a luminescent composition comprising the compound is known. 
However, there is a disadvantage that the intensity and color of light emitted from the chemiluminescent solution comprising the 9,10-diphenylanthracene compound are rendered unstable with the lapse of time.
Therefore, there have been continuous attempts to find a luminescent dye that stably emits clear blue light. In particular, due to the fact that the physical properties of the 9,10-diphenylanthracene compound change with a substituent applied to the compound, many studies have been investigated.
As one of such studies, U.S. Pat. No. 4,678,608 discloses a chemiluminescent composition using a 9,10-bis(4-methylphenyl)anthracene compound represented by the following formula 2. 
However, where the 9,10-bis(4-methylphenyl)anthracene compound is used in the chemiluminescent oxalate composition, it loses a desired stability. For this reason, the compound cannot be used in products requiring that luminescence be maintained for 5 hours or more.
Also, U.S. Pat. No. 4,717,511 discloses a chemiluminescent composition using 9,10-bis(4-methoxyphenyl)-2-chloroanthracene described in the following formula 3 
However, there is a disadvantage that the 9,10-bis(4-methoxyphenyl)-2-chloroanthracene compound emits pale blue light.
Therefore, the present inventor has endeavored to develop a compound that is capable of emitting a clear blue light for a prolonged period of time, and the present invention has been accomplished by such studies.
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an anthracene compound which has excellent stability over the conventional luminescent dye emitting blue light, thereby emitting a chemiluminescent light of clear deep blue.
It is another object of the present invention to provide a chemiluminescent composition and a chemiluminescent solution using the anthracene compound.
In accordance with one aspect of the present invention, there is provided an anthracene compound represented by the following formula(4): 
wherein R is a alkyl group having 1-8 carbon atoms, X1 and X2 are independently hydrogen or halogen.
In accordance with another aspect of the present invention, there is provided a preparation method of an anthracene compound comprising:
refluxing a compound of the following formula(11) with magnesium metal in an organic solvent and cooling the refluxed solution, thereby affording a compound of the following formula(12);
mixing the obtained compound of the formula(12) and anthraquinone of the following formula(13) in an organic solvent, refluxing the resulting solution adding an aqueous acidic solution, for example, 10% hydrochloric acid solution, extracting an organic phase, and distilling the extracted organic solvent under a vacuum, thereby producing a brown solution of the following formula(14); and
adding acetic acid and a catalyst to the obtained brown solution, and refluxing the resulting solution, thereby obtaining the solid compound of the formula(4). 
wherein R is an alkyl group having 1-8 carbon atoms, and X is halogen. 
wherein R is an alkyl group having 1-8 carbon atoms, and X is halogen. 
wherein X1 and X2 are independently hydrogen or halogen. 
wherein R is an alkyl group having 1-8 carbon atoms, and X1 and X2 are independently hydrogen or halogen. 
wherein R is an alkyl group having 1-8 carbon atoms, and X1 and X2 are independently hydrogen or halogen.
In accordance with another aspect of the present invention, there is provided a chemiluminescent composition containing the anthracene compound represented by the following formula(4): 
wherein R is a alkyl group having 1-8 carbon atoms, X1 and X2 are independently hydrogen or halogen, the chemiluminescent composition emitting chemiluminescent light by reaction with peroxide.
The present invention can be achieved by providing an anthracene compound represented by the following formula 4: 
wherein R is a alkyl group having 1-8 carbon atoms, and X1 and X2 are independently hydrogen or halogen.
A more preferred compound of the formula 4 is an anthracene compound represented by the following formula 5, in which X1 is hydrogen and X2 is halogen: 
wherein R is a alkyl group having 1-8 carbon atoms, and X2 is halogen.
A more preferred compound of the formula 5 is an anthracene compound represented by the following formula 6, in which X2 is Cl: 
wherein R is a alkyl group having 1-8 carbon atoms.
A more preferred compound of the formula 6 is 9,10-bis (4-methylphenyl)-2-chloroanthracene of the following formula 7, wherein R is a methyl group; 9,10-bis(4-ethylphenyl)-2-chloroanthracene of the following formula 8,
wherein R is a ethyl group; 9,10-bis(4-propylphenyl)-2-chloroanthracene of the following formula 9, wherein R is a propyl group; or 9,10-bis(4-t-butylphenyl)-2-chloroanthracene of the following formula 10, wherein R is a t-butyl group: 
To prepare effectively the anthracene compound of the formula 4, the present invention provides a preparation method comprising the steps of:
refluxing a compound of the following formula 11 with magnesium metal in an organic solvent for 3 hours or more, and cooling the refluxed solution, thereby obtaining a compound of the following formula 12;
stirring the obtained compound of the formula 12 and anthraquinone of the following formula 13 in an organic solvent for 3 hours or more, refluxing the resulting solution for 3 hours or more, stirring the resulting solution after adding an aqueous 10% hydrochloric acid solution, extracting only the organic solvent, and distilling the extracted organic solvent under a vacuum, thereby obtaining a brown solution of the following formula 14; and
adding acetic acid and a catalyst to the obtained brown solution, stirring the mixed solution for 1 hour or more, refluxing the stirred solution for 3 hours or more, stirring again the refluxed solution for 3 hours or more, and treating the resulting solution using a recrystallization method, thereby obtaining the solid compound of the formula 4. 
wherein R is an alkyl group having 1-8 carbon atoms, and X is halogen. 
wherein R is an alkyl group having 1-8 carbon atoms, and X is halogen. 
wherein X1 and X2 is independently hydrogen or halogen. 
wherein R is an alkyl group having 1-8 carbon atoms, X1 and X2 is independently hydrogen or halogen.
As described above, the compound of the formula 11 is refluxed with magnesium metal in the organic solvent for 3 hours or more. The refluxed solution is cooled. In this way, the compound of the formula 12 is obtained.
Various organic solvents can be used in this step. Anhydrous tetrahydrofuran is used as a preferred organic solvent in the present invention. The compound of the formula 11 and magnesium metal are added to the anhydrous tetrahydrofuran solvent at a same equivalent. The resulting solution is refluxed for 3 hours or more and then cooled.
The compound of the formula 11 may be selected from compounds having the structure of the formula 11, wherein X is halogen, and R is an alkyl group having 1-8 carbon atoms, and preferably, wherein X is halogen, and R is methyl, ethyl, propyl or t-butyl group.
The compound of the formula 12 obtained from the above step and anthraquinone of the formula 13 are stirred in the organic solvent for 3 hours or more. The stirred solution is refluxed for 3 hours or more, and stirred after being added with an aqueous 10% hydrochloric acid solution. An organic solvent is extracted, and the extracted solution is distilled under a vacuum. In this way, the brown solution of the formula 14 is obtained.
A more preferred compound of the formula 13 is an anthracene compound represented by the following formula 15, in which X1 is hydrogen, and X2 is halogen: 
wherein X2 is halogen(F, Cl or Br).
A particularly preferred compound of the formula 15 is an anthracene compound represented by the following formula 16, in which X1 is hydrogen, and X2 is halogen: 
The compound of the formula 12 and anthraquinone of the formula 13 are added to tetrahydrofuran at the same equivalent. The mixed solution is stirred for 3 hours or more, refluxed for 3 hours or more. An aqueous 10% hydrochloric acid solution is added to the refluxed solution, and stirred. An organic solvent is extracted, and the extracted organic solvent is distilled under a vacuum, by which the brown solution of the formula 14 is obtained.
Glacial acetic acid and a reducing agent are added to the brown solution. The mixed solution was stirred at room temperature for 1 hour or more, and refluxed for 3 hours or more. The refluxed solution is stirred again for 1 hour or more, by which the compound of the formula 4 was obtained using a recrystallization method in glacial acetic acid.
Various kinds of reducing agents can be selected and used as a catalyst, and SnCl2 is used preferably as the reducing agent according to the invention.
As described above, glacial acetic acid and a reducing agent are added to the brown solution of the formula 14. The mixed solution is stirred at room temperature for 1 hour or more, refluxed for 3 hours or more, and stirred again at room temperature for 1 hour or more. The resulting solution is subject to a conventional recrystallization method, by which the anthracene compound of the formula 4 is obtained in the form of solid.
The anthracene compound represented by the above The formula 4 emits light of blue series having wavelengths of 400 nm to 500 nm under prescribed conditions for obtaining chemiluminescence using conventional anthracene compounds. The anthracene compound can also generate variously colored light by proper mixing with other fluorescent dyes. Accordingly, the anthracene compound of the formula 4 according to the invention can be used as a fluorescent dye in compositions for emitting chemiluminescence light, similar to the conventional anthracene compounds.
Accordingly, the present invention provides a chemiluminescent composition comprising the anthracene compound of the formula 4, capable of generating chemiluminescence by reaction with peroxide.
Preferably, the anthracene compound of the formula 4 is present in the composition according to the present invention in an amount of 0.1 to 1.0 parts by weight, based on 100 parts by weight of the composition. Where the anthracene compound is present in an amount of less than 0.1% by weight, there is a problem that the generated light is poor in intensity and duration. Where the anthracene compound is present in an amount of more than 1.0%, the anthracene compound may be precipitated in the form of solid. Accordingly, it is preferable that the anthracene compound is contained in the prescribed range. More preferably, the anthracene compound is present in the composition in an amount of, 0.15 to 0.5 parts by weight, based on 100 parts by weight of the composition.
More preferably, the anthracene compound of the formula 4 is selected from the group consisting of 9,10-bis(4-methylphenyl)-2-chloroanthracene, 9,10-bis(4-ethylphenyl)-2chloroanthracene, 9,10-bis(4-propylphenyl)-2-chloroanthracene and 9,10-bis(4-t-butylphenyl)-2-chloroanthracene.
The chemiluminescent composition comprising the anthracene compound of the formula 4 also comprises a solvent. According to the present invention, the solvent may be selected from the group consisting of tertiary alcohols, dibutyl phthalate, butyl benzoate and the mixtures thereof.
The chemiluminescent composition according to the present invention also contains an oxalate compound. Preferably, bis(2,4,5-trichloro-6-carbopentoxyphenyl)oxalate may be used as the oxalate compound.
According to the invention, the oxalate compound is present in the composition in an amount of 5 to 18 parts by weight, based on 100 parts by weight of the composition. Where the oxalate compound is present in an amount of less than 5.0 parts by weight, based on 100 parts by weight of the composition, the intensity of light will be very weak. Where the oxalate compound present in an amount of more than 18%, there will be a problem in that the oxalate compound is precipitated in the form of solid. Accordingly, it is preferable that the oxalate compound is contained in the prescribed range. More preferably, the oxalate compound is present in the composition in an amount of 9.0 to 15.0 parts by weight, based on 100 parts by weight of the composition.
The chemiluminescent composition according to the present invention may generate chemiluminescence by reaction with peroxide. As described above, the chemiluminescent composition comprising anthracene of the formula 4 emits blue light of 400 to 500 nm by reaction with peroxide.
In this regard, the present invention provides a chemiluminescent solution containing the chemiluminescent composition and a solution containing peroxide.
Preferably, the chemiluminescent composition and the peroxide-containing solution are mixed in a ratio of 1:1 to 5:1. Where the ratio of the chemiluminescent composition to the peroxide-containing solution is less than 1:1, the duration of chemiluminescence will be shorter. Where the ratio of the chemiluminescent composition to the peroxide-containing solution is more than 5:1, the initial chemiluminescence is weak. Accordingly, it is preferable that the chemiluminescent composition and the solution containing peroxide are mixed in the prescribed range. More preferably, the chemiluminescent composition and the peroxide-containing solution are mixed in a ratio of 2.5:1 to 3.5:1.
It is preferable that the peroxide-containing solution contains peroxide in an amount of 0.5 to 5 parts by weight, based on 100 parts by weight of the solution. Where peroxide is present in the solution in an amount of less than 0.5 parts by weight, based on 100 parts by weight of the solution, the initial chemiluminescence will be weak. Where peroxide is present in an amount of more than 5%, the intensity of initial chemiluminescent light is so high that the duration of chemiluminescence is shorter. Accordingly, it is preferable that peroxide is present in the prescribed range. The peroxide-containing solution more preferably contains peroxide in an amount of 1 to 3 parts by weight, based on 100 parts by weight of the solution. Peroxide may be hydrogen peroxide or peroxides of carboxylic acid and the like, but is preferably hydrogen peroxide in view of reactivity.
The peroxide-containing solution also contains a solvent. According to the present invention, the solvent is selected from the group consisting of tertiary alcohol, dimethyl phthalate, dibutyl phthalate, butyl benzoate and the mixtures thereof.
Further, the peroxide-containing solution contains a catalyst. In the present invention, salicylate is preferably used as the catalyst. The catalyst is preferably present in the solution in an amount of 0.003 to 0.03 parts by weight, based on 100 parts by weight of the solution.
When the peroxide-containing solution having the above composition is mixed with the chemiluminescent composition of the present invention in the prescribed ratio, deep blue chemiluminescence lasts for 5 to 48 hours or more, and afterglow lasts for 60 hours or more.
The chemiluminescent light generated by the present composition can be used in common application fields, for example, for signaling, decoration, games, hunting, fishing or military purposes.
Now, examples of the present invention will be described in more detail. The following examples are described only for a better understanding of the present invention, and are not intended to limit the invention.